Cooking units of the liquid vat type are commonly used in restaurants for cooking french fries and the like. A body of hot oil or other liquid is maintained at a temperature level suitable for cooking purposes, and food products to be cooked are immersed therein for the requisite length of time.
Such cooking units are typically designed to receive their cooking energy from natural gas. A gas burner is placed underneath the vat. An air inlet conveys fresh, combustible air through a confined passageway to the burner, and after combustion the heated air and combustion products of the gas flow through an exhaust passageway which is in thermal communication with the vat, thereby heating the vat and its liquid contents.
In cooking units of this type, as in other gas appliances, the gas burner is turned on to burn at full force and then, after a requisite amount of heat has been generated, it is turned off. Eventually the temperature of the liquid body drops below a control level, and then the burner is turned on again.
Cooking units of the type referred to have provided very satisfactory service, particularly in the fast food type of restaurant. Nevertheless, it is the purpose of te present invention to provide an improved form of such cooking apparatus, as well as a method of using same, for the specific purpose of conserving the energy supply.